Attachment for coupling detachable and permanently installed components for dental prostheses to each other

ABSTRACT

The detachable component of a dental prosthesis is releasably secured to the permanently installed component by one or more pairs of male and female detent members. Each male detent member has a miniature flat brick-shaped compartment for a flat serpentine (particularly U-shaped or S-shaped) or a flat block-shaped spring whose front portion can bias or constitute a plunger which extends from the compartment and snaps into the respective female detent member. The male detent member or members are mounted on the detachable component and the female detent member or members are provided in or on the permanently installed component, preferably very close to the gum of the respective jaw. The casing which defines the compartment of the male detent member can be a prefabricated part or it may be formed, at least in part, during casting of the metallic part or parts of the detachable component. The overall dimensions of the male detent member need not exceed 5×3.5×1 mm.

CROSS-REFERENCE TO RELATED CASE

This is a continuation-in-part of my copending patent application Ser.No. 655,025 filed Sept. 26, 1984, now U.S. Pat. No. 4,586,902 grantedMay 6, 1986.

BACKGROUND OF THE INVENTION

The present invention relates to improvements in separable attachmentsbetween installed and removable components of dental prostheses. Moreparticularly, the invention relates to improvements in so-calledspring-loaded retention elements of the type wherein the female detentelement is normally positioned below the survey line and the male detentelement can snap into the female detent element by spring action. Theinvention also relates to a method of making the attachment and toimprovements in means for facilitating the practice of the method.

In presently known attachments of the above outlined character, the maledetent member comprises a flexible or bendable spring which isreceivable in the recess of the female detent member (also known simplyas female). The flattest conventional male detent member uses a springwhich is made of wire having a diameter of 0.7 mm or thereabout, andsuch wire is inserted into a compartment with certain freedom ofmovement for penetration into or expulation from the recess of thefemale detent member. The overall thickness of the male detent memberincluding the receptacle for the spring is in the range of 2 mm.

Certain other presently known attachments of the above outlinedcharacter comprise male detent members wherein a plunger is reciprocableunder the action of a coil spring so that its head can penetrate intothe recess of the female detent member. The minimum diameter of theplunger is 2.9 mm and the overall thickness of the male detent member iswell in excess of the diameter of the plunger since the latter must bereceived, with a certain amount of play, in a suitable cylinder which isinstalled in the detachable or in the permanently installed component ofthe prosthesis. However, the overall dimensions of male detent memberswhich employ reciprocable plungers are smaller than those of the maledetent members employing the aforementioned bendable spring because thebendable spring occupies more room than the plunger and the coil springtherefor. Moreover, the bendable spring must be adequately anchored inthe corresponding component of the prosthesis. Attempts to reduce theoverall dimensions of male detent members which employ bendable springshave failed because a very small spring cannot be properly manipulatedby the dental technician and also because the time which is required forproper installation of a very small spring would render the cost of theprosthesis employing two or more male detent members with miniaturesprings prohibitively high.

OBJECTS AND SUMMARY OF THE INVENTION

An object of the invention is to provide a novel and improved attachmentwhich can be used to separably secure a detachable component of a dentalprosthesis to the component which is permanently or more or lesspermanently installed in the mouth of the wearer.

Another object of the invention is to provide an attachment which canemploy male and female detent members whose dimensions are a minutefraction of the dimensions of presently known male and female detentmembers but which is nevertheless capable of reliably holding thedetachable component in proper position relative to the permanentlyinstalled component of the prosthesis.

A further object of the invention is to provide a novel and improvedmale detent member which can be used in an attachment of the aboveoutlined character.

An additional object of the invention is to provide a male detent memberwhose thickness can be less than 1 mm and which can be installed inexisting or in newly made components of dental prostheses in asurprisingly simple material- and time-saving manner.

Still another object of the invention is to provide a male detent memberwhich need not necessarily employ a discrete plunger and wherein a novelspring can serve as a means for actually holding the male detent memberin proper engagement with the female detent member.

An additional object of the invention is to provide a novel and improvedmethod of making the male detent member and of installing such detentmember in the corresponding component of the prosthesis.

Still another object of the invention is to provide novel and improvedmeans for facilitating the practice of the just outlined method.

Another object of the invention is to provide a novel and improveddental prosthesis which embodies one or more detent members of the aboveoutlined character.

A further object of the invention is to provide novel and improveddetachable and/or permanently installed components of dental prostheseswhich embody detent members of the above outlined character.

One feature of the invention resides in the provision of an attachmentbetween stationary (namely more or less permanently installed) andremovable (e.g., bridge-like) components of a dental prosthesis. Theattachment comprises a female detent member in or on one of thecomponents (at the present time, the female detent member is preferablyprovided in or on the stationary component) and a male detent memberwhich comprises a flat hollow casing provided in the other component andhaving an opening. The male detent member further comprises a flatserpentine (e.g., U-shaped or S-shaped) spring or a flat block-shapedspring which is installed in the casing, and a flat plunger which isbiased by the spring to normally extend from the casing through theaforementioned opening and is receivable in the female detent member.The plunger can constitute or can be bonded to the front portion of thespring. The one component includes a portion which is adjacent to thegum of the respective jaw of the wearer of the prosthesis, and thefemale detent member is preferably provided in such portion of the onecomponent, i.e., close to the gum.

The front portion of a serpentine spring is preferably straight orsubstantially straight and preferably extends only partially beyond theopening of the casing while it is received in the female detent member.The casing is preferably provided with a substantially rectangular flatcompartment for the spring and, if the latter is a serpentine spring, itpreferably comprises two additional portions which flank the frontportion and are slidable along two spaced-apart parallel internal guidesurfaces of the casing. The cross-sectional outline of the serpentinespring is preferably a polygon (most preferably a square or a rectangle)and the front portion of the serpentine spring preferably tapers in adirection away from the interior of the casing. Anchoring means (e.g., aprojection on the spring and a complementary recess or hole in thecasing) can be provided to secure the serpentine spring in the casing insuch a way that the front portion of the serpentine spring is movablerelative to the casing during insertion of the removable component into,or during removal of such component from, the mouth of the wearer. Themaximum dimension of the cross section of the spring is preferably lessthan 0.7 mm, most preferably between 0.35 and 0.5 mm.

A block-shaped spring can be made of a rubber-like material (e.g.,silicone rubber) and can substantially fill the compartment of thecasing. The first end portion of such spring can be bonded to aseparately produced metallic plunger.

In accordance with a presently preferred embodiment of the invention,the attachment can constitute a so-called friction grip slide attachmentwith a female part and a male part which latter is receivable in and isslidable relative to the female part. One of these parts is provided onthe one component and the other part is provided on the other component.The detent members are provided on the corresponding parts and serve toreleasably hold the male part against movement relative to the femalepart after the male part is properly inserted into the female part. Themale and female parts are or can be made integral with the respectivedetent members.

Another feature of the invention resides in the provision of a method ofmaking a separable attachment of the above outlined character, i.e., anattachment between stationary and separable or detachable components ofa dental prosthesis wherein one of the components carries a femaledetent member and the other of the components carries a male detentmember having a flat hollow casing with an opening and a serpentine orblock-shaped spring installed in the casing and including a frontportion which constitutes or carries a plunger that normally extendsfrom the casing through the opening and is receivable in the femaledetent member. The method comprises the steps of making a pattern of theother component (e.g., a pattern which is made of wax or a castingresin), installing the pattern and the male detent member in a castingmold, evacuating the material of the pattern (e.g., by heating the mold)so as to leave in the mold a cavity for reception of flowable metallicmaterial, introducing the metallic material into the cavity, andintegrating the male detent member into the thus obtained othercomponent. The casing is preferably made of a metallic material, and themethod preferably further comprises the step of prefabricating at leasta portion of the casing prior to the installing step. For example, thecasing can be made of a single piece of metallic material or of twoportions which are assembled to define a compartment for the spring. Thecasing and the other component preferably consist of alloys which aremelted into each other in the course of the integrating step while thecasing retains its shape to ensure that it can properly receive thespring. The method preferably further comprises the steps of inserting aprefabricated brick-shaped casting core into the casing prior to theinstalling step, removing the core from the casing upon completion ofthe integrating step, i.e., after the flowable metallic material of theother component is allowed to harden in the cavity of the mold, removing(e.g., extracting) the core from the interior of the casing uponcompletion of the integrating step, and installing the spring in thecasing subsequent to such removing step.

A further feature of the invention resides in the provision of acombination of parts which can be used with advantage for the practiceof the above outlined method. Such combination includes a flatblock-shaped casting core and a casing having walls which surround atleast four sides of the core (for example, at least one of the twosmaller end faces of the flat brick-shaped core can remain exposed). Thecore is removable from the casing so that the latter can receive aspring a portion of which preferably constitutes a plunger that extendsfrom the casing and is receivable in the female detent member. Inaccordance with one presently preferred embodiment, the casing comprisesa substantially U-shaped first portion which surrounds three sides ofthe casting core and a second portion which forms with the first portiona flat tube and is adjacent to a fourth side of the core. The casing canbe provided with a handle (e.g., a relatively large rib) and with atleast one hole in the handle so that the latter can be attached to theframe of a bridge or the like.

Furthermore, the casing can comprise at least one extension (e.g., inthe form of a lug which constitutes an integral part of theaforementioned U-shaped first portion) which is arranged to be embeddedin forming sand in a casting mold wherein the casing is connected withthe other component of the prosthesis. The casing is normally elongatedand the aforementioned extension or extensions are preferably providedat one end of the elongated casing.

An additional feature of the invention resides in the provision of a kitfor the making of a male detent member for use as a part of a separableattachment between stationary and removale components of a dentalprosthesis wherein the male detent member is installed in one of thecomponents and cooperates with a female detent member in the othercomponent to separably couple the components to each other. Inaccordance with one presently preferred embodiment, the kit comprises aprefabricated flat hollow casing which defines the aforementioned flatcompartment having a width greatly exceeding its height and is providedwith an opening which communicates with the compartment, a flat spring(e.g., a serpentine metallic or plastic spring, a serpentine springembedded in a soft mass of silicone rubber or the like, or ablock-shaped spring of silicone rubber or the like) which is insertableinto the compartment and has a width and a height respectivelyapproximating the width and height of the compartment in the casing, anda plunger (which can be bonded to, made integral with or movableindependently of the spring) which is arranged to be biased by thespring upon insertion of the spring and plunger into the compartment sothat the plunger normally extends from the casing through the openingunder the bias of the spring and can penetrate into the socket of afemale detent member in a dental prosthesis. A common envelope can beprovided for the casing, for the spring and for the plunger. Stillfurther, such kit can comprise a prefabricated casting core which isused for the making of the casing and which can remain in thecompartment of the casing during installation of the casing in onecomponent of a dental prosthesis.

If the casing is to be formed around the casting core by the party whohas purchased the kit, the latter can comprise only a prefabricatedcasting core and a prefabricated serpentine, block-shaped or othersuitable spring (with a plunger bonded to the spring, with a plungerforming an integral part of the spring or with a plunger constituting aseparate part).

If the casing is partly prefabricated, the kit can comprise one or more(e.g., U-shaped) casing portions which preferably partially orcompletely surround the casting core in the envelope of the kit. Suchenvelope is designed for joint shipment of prefabricated parts to adental technician or to a dental laboratory.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved attachment itself, however, both as to its construction and themode of making and assembling the same, together with additionalfeatures and advantages thereof, will be best understood upon perusal ofthe following detailed description of certain specific embodiments withreference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an enlarged sectional view of a male detent member which canbe used in the improved attachment, the section being taken in thedirection of arrows as seen from the line I--I of FIGS. 2 or 3;

FIG. 2 is a sectional view of the male detent member as seen in thedirection of arrows from the line II--II of FIG. 1;

FIG. 3 is a sectional view of the male detent member as seen in thedirection of arrows from the line III--III of FIG. 1;

FIG. 4 is a fragmentary perspective partly sectional view of a dentalprosthesis which employs the male detent member of FIGS. 1 to 3;

FIG. 5 is a fragmentary perspective partly sectional view of a differentprosthesis which employs the male detent member of FIGS. 1 to 3;

FIG. 6 is a fragmentary partly sectional view of a third prosthesiswhich employs the male detent member of FIGS. 1 to 3;

FIG. 7 is a fragmentary perspective view of a fourth prosthesis whichemploys the male detent member of FIGS. 1 to 3, the male detent memberbeing provided on a male part or connector which is detached from thecomplementary female part of connector;

FIG. 8 is a plan view of the structure which is shown in FIG. 7, withthe male part inserted into the female part and with the male detentmember engaging the female detent member;

FIG. 9 is a different perspective view of the structure which is shownin FIG. 7;

FIG. 10 is a sectional view of a modified male detent member whosecasing has a handle or rib for connection to the frame of a bridge oranother separable component of a dental prosthesis;

FIG. 11 is a sectional view as seen in the direction of arrows from theline XI--XI of FIG. 10;

FIG. 12 is a perspective view of the main or first portion of the casingof the male detent member which is shown in FIGS. 10 and 11;

FIG. 13 is an exploded perspective view of a permanently installedsection of a crown which is provided with a female detent member and ofa wax pattern which is about to be assembled with a male detent memberof the type shown in FIGS. 10 and 11;

FIG. 14 illustrates the crown section of FIG. 13 and the finisheddetachable crown section which carries a male detent member of the typeshown in FIGS. 10 and 11;

FIG. 15 illustrates the structure of FIG. 14 plus an additional portionof a bridge which includes the detachable crown section and the maledetent member;

FIG. 16 is a schematic view of a casting mold for the making of thedetachable crown section of FIGS. 14-15 and for permanent incorporationof a male detent member thereinto;

FIG. 17 is an enlarged perspective view of the detachable crown sectionand of the male detent member upon removal from the mold of FIG. 16;

FIG. 18 is a fragmentary perspective view of a crown section and of amale detent member which is somewhat similar to the male detent memberof FIGS. 1 to 3;

FIG. 19 is a sectional view of a modified spring which is bonded to aseparately produced plunger;

FIG. 20 is a sectional view of a further spring; and

FIG. 21 is a schematic elevational view of a kit with a prefabricatedcasting core and other parts which can reduce the amount of manual workin connection with the making of a male detent member and itsinstallation in a component of a dental prosthesis.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first to FIGS. 1 to 3, there is shown the male detent member 1of an attachment which embodies one form of the invention. The maledetent member 1 comprises a flat casing 2 which is made of an alloy thatis customarily employed by dentists in connection with the making ofprostheses. For example, the casing 2 can be made from a chromium-cobaltalloy or from an alloy which contains a noble metal. The casing 2comprises a relatively thick solid block-shaped bottom wall 3, twospaced-apart flat parallel sidewalls 2a and two spaced-apart parallelend walls 2b. The walls 2a, 2b and 3 define a flat prismatic compartment2c and the walls 2a, 2b define an opening 2d which is remote from and islocated opposite the bottom wall 3. The casing 2 is an elongated flatbrick-shaped body which can have the following dimensions: a thicknessof 0.9 mm, a width of 3.5 mm and a length of 5 mm. The thickness of eachof the sidewalls 2a and end walls 2b can be in the range of 0.2 mm.

The male detent member 1 further comprises a serpentine spring 4 whichis installed in the compartment 2c and whose loops are disposed in asingle plane, namely in a plane which is parallel to and is disposedbetween the planes of the sidewalls 2a. The spring 4 constitutes alength of suitably bent wire having a polygonal (preferably rectangularor square) cross-sectional outline (see FIG. 3). For example, the lengthof the sides of the square cross-section of the wire which constitutesthe serpentine spring 4 can be in the range of 0.4 mm. Thus, the spring4 is received in the compartment 2c with a play which is in the range of0.1 mm (provided that the thickness of the casing 2 is 0.9 mm and thethickness of each sidewall 2a is 0.2 mm). The innermost portion of thespring 2 is configurated in such a way that it contacts the inner sideof the bottom wall 3 at two spaced-apart locations 5 and 6. Theillustrated serpentine spring 4 is a substantially S-shaped body and itsconfined end portion 7 has a lateral projection which is anchored in ahole 8 provided in the adjacent end wall 2b so that the spring isadequately anchored against accidental removal from the casing 2.

The outermost or front portion 9 of the spring 4 constitutes a plungerwhich normally extends in part from the casing 2, i.e., beyond theopening 2d and preferably constitutes a straight elongated elementhaving a substantially V-shaped cross-sectional outline (see FIG. 2) sothat it can more readily penetrate into the recess which is defined bythe corresponding female detent member 12 (FIG. 4). That end portion(10) of the spring 4 which is remote from the bottom wall 2 is bentinwardly from the respective end of the front portion 9 and is slidablyguided by the inner side of the respective end wall 2b. The end portion10 cooperates with a further portion 11 of the spring 4 to ensure thatthe front portion 9 is adequately guided for movement toward and awayfrom the bottom wall 3 without any or without appreciable changes in itsorientation. The portion 11 is slidable along the inner side of theadjacent end wall 2b, namely along the inner side of that end wall whichhas the hole 8 for the projection of the end portion 7. The portions 10,11 flank the front portion 9.

When the male detent member 1 is installed in the stationary orremovable component of a dental prosthesis, preferably in the removablecomponent such as the bridge 14 which is shown in FIG. 4, the frontportion 9 is caused to penetrate into the compartment 2c while thebridge 14 is in the process of moving toward its inserted position andthe front portion 9 is then permitted to move outwardly so that itpenetrates directly into the recess or socket of the female detentmember 12 which is provided in or on the stationary (installed)component of the prosthesis.

FIG. 4 shows a tooth 13 which carries a crown, and an artificial tooth15 which is mounted on the bridge 14. When the bridge 14 is properlyattached to the crown of the tooth 13, the latter is adjacent to thefalse tooth 15. The stump or stub 16 of the tooth 13 extends downwardlyfrom the gum G and the crown of the tooth 13 comprises a frustoconicalinner section 17 which surrounds the exposed part of the stub 16 and themajor portion of which is, in turn, surrounded by an outer crown section19 that resembles the exposed part of a tooth and is permanently securedto the cast metallic frame 20 of the bridge 14 by a layer 18 of solder.Thus, the inner crown section 17 constitutes the fixed or permanentlyinstalled component of the prosthesis and the outer crown 19 forms partof the removable component or bridge 14 of the prosthesis. Theaforementioned casing 2 of the male detent member 1 is recessed into themetallic frame 20 of the bridge 14, and the space between its externalsurface and the surface bounding the recess in the frame 20 is filledwith a mass 21 of suitable hardened synthetic plastic material. Theouter side of one of the sidewalls 2a of the casing 2 can be providedwith a set of anchoring elements 22 to further reduce the likelihood ofaccidental or unintentional separation of the casing 2 from the frame 20of the bridge 14. The male detent member 1 can be mounted in an existingbridge 14 or it can be installed in the recess of the frame 20 duringthe making of the bridge.

The female detent member 12 forms part of the inner section 17 of thecrown 17, 19 for the stub 16 of the tooth 13. When the bridge 14 isproperly installed in the mouth of the wearer of the prosthesis, theinner crown section 17 depresses the front portion 9 of the spring 4into the compartment 2c of the casing 2, at least during the last stageof insertion of the bridge, and the front portion 9 is thereupon causedto move outwardly due to innate resiliency of the spring 4 andpenetrates into the recess or socket of the female detent member 12 toensure adequate retention of the bridge in the mouth. At such time, theouter crown section 19 (which is an integral part of the bridge 14)overlies and conceals the inner crown section 17 on the stub 16 of thetooth 13. The bias of the spring 4 (i.e., the resistance of the spring 4to deformation which involves penetration of the entire front portion 9(or of the major part of the front portion 9) into the compartment 2c ofthe casing 2) is selected with a view to prevent accidental detachmentof the male detent member 1 from the female detent member 12, i.e., toensure that the wearer of the bridge 14 must exert a reasonable force inorder to push the front portion 9 back into the compartment 2c in orderto detach the male detent member 1 from the female detent member 12. Thelayer 18 of solder is relatively large and is adjacent to a portion ofthe mass 21 of hardened synthetic plastic material in the recess of theframe 20.

An important advantage of the improved male detent member 1 is that itconstitutes a prefabricated product which can be readily incorporated inthe corresponding component of the prosthesis (as a rule, the maledetent member will be installed in the detachable component because itcan be readily inspected whenever the detachable component is removedfrom the mouth of the wearer; however, it is equally possible to providethe detent member 1 in or on the permanently installed component of theprosthesis). Another important advantage of the detent member 1 is thatit is extremely small but is nevertheless capable of cooperating withthe female detent member 12 to adequately hold the detachable componentof the prosthesis in proper position with reference to the permanentlyinstalled component. The serpentine spring 4 takes up a very smallamount of space so that the casing 2 can be formed with a flatcompartment 2c whose height (between the sidewalls 2a) need notappreciably exceed the maximum dimension of the cross section of thespring 4. Such serpentine springs can be mass produced in any desiredsize and/or shape at a very low cost, and their insertion into therespective compartments 2c presents no problems. Adequate anchoring ofan inserted spring 4 is ensured by the aforementioned anchoring means 7,8 or by analogous or other suitable anchoring means. All a technicianhas to do is introduce the proper end of the spring 4 into thecompartment 2c by way of the opening 2d to such an extent that theprojection 7 snaps into the hole 8 whereby the spring is properlyanchored in the casing 2 and its front portion 9 extends partly throughand outwardly beyond the opening 2d. The feature that the front portion9 tapers in a direction away from the interior of the casing 2facilitates the introduction of such front portion into the femaledetent member as well as extraction of the front portion from the femaledetent member 12 when the wearer or a dentist desires to extract thecomponent 14 from the wearer's mouth. It has been found that, in spiteof its miniature size, the improved male detent member 1 can cooperatewith the female detent member 12 to properly hold a detachable component(such as 14) which had to be provided with unsightly and bulky clamps ifit was to be properly inserted in accordance with heretofore knowntechniques.

Another important advantage of the male detent member 1 is that itscasing 2 is not only extremely flat but also that the width and thelength of the casing are surprisingly small. Thus, a serpentine spring 4of adequate strength can be readily accommodated in a very smallcompartment 2c and is adequately guided therein because the springportions 10, 11 which flank the front portion 9 are slidable along theadjacent internal surfaces of the parallel end walls 2c of the casing 2.The feature that the spring 4 can be installed in a casing 2 whose widthand length are also small or extremely small is highly desirable in manytypes of prostheses because the detent member 1 must be installed inthat portion of the component 14 or another detachable component whichis subjected to maximum stresses when the prosthesis is in use. The justmentioned portion of the component 14 is that portion which is separablycoupled to the component 17 by way of the detent members 1 and 12.

The feature that only a part of the front portion 9 of the spring 4extends from the casing 2 when such front portion is received in therecess of the female detent member 12 or when the component 14 isdetached from the component 17 is desirable and advantageous because theconfined part of the front portion 9 at least substantially seals theopening 2d and thus prevents penetration of foreign matter into thecompartment 2c. Moreover, such mounting of the spring 4 enhances itsability to stand pronounced stresses and to reliably hold the component14 in place except when the wearer or the dentist desires to detach thecomponent 14 from the component 17. The utilization of a spring having apolygonal (preferably square or rectangular) cross-sectional outline isdesirable and advantageous because such spring is in largesurface-to-surface contact with and is adequately guided by the casing2. Moreover, such a spring (and more particularly its front portion 9)is more likely to adequately seal the opening 2d to thus preventpenetration of foreign matter into the compartment 2c. Still further,the maximum transverse dimension of the square or substantially squarecross section of a wire is less than the diameter of a round wire havingthe same cross-sectional area. As mentioned above, the maximum dimensionof the cross-section of the spring 4 need not exceed 0.7 mm and ispreferably between 0.35 and 0.5 mm.

FIG. 5 shows the manner in which the male detent member 1 is installedin a different detachable or removable component 23 of a dentalprosthesis. The connecting yoke 24 between the illustrated half of thedetachable component 23 and the other half (which also carries a maledetent member 1) is broken away, as at 25. The front portion 9 of thespring 4 in the casing 2 of the male detent member 1 shown in FIG. 5extends into the recess of a female detent member 12 forming part of asolid beam 26 which is rigidly connected to the crowns of twospaced-apart teeth, one in front of and the other behind the plane ofFIG. 5. The reference character 27 denotes a tooth in the lower jaw ofthe wearer of the prosthesis. The beam 26 forms part of the permanentlyinstalled component, and the structure 23 is the removable or detachablecomponent of the prosthesis. A surface 28 at the underside of theproperly inserted component 23 is located opposite the top surface ofthe tooth 27. The exposed front side of the component 23 carries afacing or liner 29 which is made of a ceramic or synthetic plasticmaterial and constitutes a false tooth.

The manner in which the casing 2 of the male detent member 1 isinstalled in the detachable component 23 of the prosthesis is analogousto that which was described with reference to FIG. 4. Thus, the yoke 24of the component 23 has a recess which is large enough to receive thecasing 2 with some room for a mass 30 of hardened synthetic plasticmaterial or solder which ensures adequate retention of the casing 2 inthe yoke 24 under all foreseeable circumstances. As mentioned above, thefemale detent member 12 is provided on the beam 24 of the fixedlyinstalled component of the prosthesis and its recess receives the frontportion 9 of the serpentine spring 4 in the compartment 2c of the casing2 when the component 23 is properly inserted. The reference character 31denotes a layer of solder which connects the yoke 24 of the component 23with the facing or liner 29. Due to its rather insignificant thickness,the entire casing 2 of the male detent member 1 can be fully recessedinto the yoke 24 without undue weakening of the corresponding portion ofthe detachable component 23. In fact, the illustrated casing 2 isrecessed into the yoke 24 at a level above the layer 31 of solder orhardened synthetic plastic material. The height of the illustrated beam26 is in the range of 2 mm. If desired, the casing 2 can constitute anintegral part of the casting which is the yoke 24 so that the mass 30can be omitted.

FIG. 6 shows a crowned tooth 32 in the mouth of the wearer and a falsetooth 34 which is provided on the removable or detachable component 33of the prosthesis. The teeth 32 and 34 are adjacent to each other. Thetooth 32 extends downwardly from the upper jaw and the teeth 32, 34 arelocated in front of two teeth 35, 36 in the lower jaw. The inclinedfront sides of the teeth 35, 36 are adjacent to the complementary rearsides of the teeth 32, 34 when the wearer's mouth is closed. Thisprovides very little room for the removable component 33 of theprosthesis, i.e., for the component which, in the embodiment of FIG. 6,carries the male detent member 1 and includes a cast metallic frame.

The drowned tooth 32 includes an exposed and visible outer crown section32a which is located in front of the tooth 35 and whose uppermost part38 surrounds and is removably mounted on the inner crown section 37surrounding the stub of the respective tooth in the upper jaw. Thesection 32a forms part of the removable component 33 of the prosthesis.The female detent member 12 is provided on the inner crown section 37which constitutes or forms part of the permanently installed componentof the prosthesis. The casing 2 of the male detent member 1 is recessedinto the metallic frame of the removable component 33. A layer 39 ofsolder is provided to connect the metallic frame of the component 33with the portion 38 of the outer crown section 32a.

The structure which is shown in FIG. 6 is a typical example of aprosthesis whose removable component 33 could not be adequately andreliably installed in the mouth without resorting to clamps or the likewere it not for the extremely small and flat male detent member 1 whichrenders it possible to provide the complementary female detent member 12on the inner section 37 of the crown for the tooth 32 in immediateproximity of the gum G.

FIGS. 7 to 9 illustrate the manner in which the improved male and femaledetent members can be installed in a prosthesis wherein the attachment51 between the permanently installed and detachable components of theprosthesis is a so-called friction grip slide attachment with a femalepart 53 embedded in the crown 52 of a tooth extending from the lower jawof the wearer and a complementary male part 55 installed on thedetachable component (not shown) of the prosthesis. The lowermostportion of the female part 53 includes a female detent member 54 (FIG.9) and the corresponding portion of the male part 55 includes a maledetent member 1 of the type shown in FIGS. 1 to 3. The housing 2 of themale detent member 1 is integral with the male part 55 of the attachment51. The male part 55 further comprises a handle or rib 56 having twoholes for fasteners which secure the part 55 to the detachable componentof the prosthesis, e.g., to the cast metallic frame of a bridge. FIG. 7shows the attachment 51 prior to insertion of the T-shaped rail of themale part 55 into the complementary slot of the female part 53. In FIG.8, the parts 53 and 55 are assembled and the front portion 9 of theserpentine spring 4 in the casing 2 of the male detent member 1 isassumed to extend into the recess of the female detent member 54 on orin the female part 53 of the attachment 51 so as to hold the part 55against movement relative to the part 53.

An important advantage of the structure which is shown in FIGS. 7 to 9is that the length of the male and female parts 55, 53 can be reduced toa fraction of the length of similar parts in conventional attachments.This is due to the fact that the miniature male detent member 1 sufficesto ensure reliable retention of a relatively short male part 55 in anequally short female part 53. The parts 53, 55 are or can beprefabricated, and they can be readily assembled with the correspondingdetent members. Thus, the female detent member 54 can be formed byproviding the corresponding portion of the female part 53 with asuitable notch or groove, and the casing of the male detent member 1 canconstitute an integral part of the respective end portion of the malepart 55.

FIGS. 10 to 12 illustrate a different male detent member which has amodified casing including a U-shaped first or main section 40 and aU-shaped second section 41 constituting a baked cover or lid which canconsist of a pattern making material. As can be seen in FIG. 12, themain section 40 is made of a sheet or blank of metal by bending thesidewalls 42 and a bottom wall 43 from the general plane of theremainder of the blank. The extensions or lugs 44 of the sidewalls 42extend rearwardly beyond the bottom wall 43. The width of the sidewalls42 is the same as that of the bottom wall 43 so that each of theextensions 44 has a substantially square outline. The U-shaped cover orlid 41 has two sidewalls or cheeks 45 which overlie the outer sides ofthe sidewalls 42 of the main portion 40. The central portion of thecover 41 has an outwardly extending handle or rib 47 with two circularholes 46 for attachment to the removable component of the prosthesis.The rib 47 has a substantially triangular shape and is integral with theremainder of the cover 41 in the region of the bottom wall 43. Thematerial of the rib 47 is preferably the same as that of the cover 41.

The serpentine spring 48 in the flat compartment of the casing includingthe main portion 40 and cover 41 is substantially identical with thespring 4 of the male detent member 1 shown in FIGS. 1 to 3. This springhas a substantially square cross-sectional outline and its confined endportion may but need not have a projection such as the projection of theend portion 7 shown in FIG. 1. The innermost portion 49 of the spring 48is straight and abuts against the inner side of the bottom wall 43. Theconcealed inner end portion 50 is also straight and abuts against theinner side of the respective sidewall 42. It will be noted that thespring 48 is not positively anchored in the compartment of the casingincluding the main portion 40 and the cover 41. This renders it possibleto readily insert such spring after the casing 40, 41 is alreadyintegrally connected to the respective component of the prosthesis. Atthe time the casing 40, 41 is being attached to the correspondingcomponent of the prosthesis, the compartment within the casing is filledby a casting core 77 (FIG. 18) which, together with the casing 40, 41,constitutes a pattern 60 adapted to be used in a manner as shown in FIG.13. The core 77 completely fills the compartment which is defined by theportions 40 and 41 of the casing. FIG. 13 shows a crown section 61 whichforms part of the fixedly installed component of the prosthesis. Thecrown section 61 is formed with two tapering grooves 62 for twocomplementary tapering male parts on a second crown section 63 (FIGS. 14and 15). The opening 67 in a wax pattern 69 (FIG. 13) of the crownsection 63 serves to receive a portion of the casing including theportions 40, 41, and the hole 68 of the pattern 69 serves to receive aportion of the handle or rib 47. The sections 61 and 63 togetherconstitute a complete crown for the stub or stump of a tooth T. In orderto make the detachable crown section 63 of a suitable metallic alloy, itis necessary to make the pattern 69 of wax or another material which canbe removed by heating, and such pattern 69 is then embedded in a castingmold 65 containing molding sand 66 or another heat- and fire-resistantmaterial (see FIGS. 16 and 17).

The manner in which the pattern 69 is assembled with the element 60 isshown in FIG. 13. The pattern 69 is made by hand and is then assembledwith the element 60. The openings or holes 67, 68 respectively receiveportions of the casing 40, 41 and rib or handle 47. The mode ofinsertion is such that the open end of the compartment in the casing 40,41 (actually, the compartment is filled by the aforementioned core) isleading during insertion into the opening 67 of the handmade pattern 69and that the narrower upper portion of the handle or rib 47 is leadingduring insertion into the opening 68. The openings 67, 68 are completelyfilled when the element 60 is properly assembled with the hand-madepattern 69. The areas where the exposed surface of the pattern 69surrounds the outwardly extending portions of the rib 47 and the casing40, 41 are thereupon smoothed by addition of wax in a manner as shown inFIG. 14. Such added material strengthens the connection between theelement 60 and pattern 69. FIG. 13 further shows that the open end ofthe compartment in the casing 40, 41 of the element 60 will be locateddirectly in front of a recess or notch 70 (female detent member) whichis machined into the external surface of the crown section 61 adjacentto the gum. When the core is removed and the compartment of the casing40, 41 receives a serpentine spring 48 (which is shown in FIG. 10 onlyfor the sake of clarity), the straight front portion 48a or plunger ofsuch spring is free to extend into the recess 70.

FIG. 16 shows the composite pattern (including the element 60 and thewax pattern 69) in the casting mold 65 with some of the sand 66 removedin the region immediately around the pattern 69 for the sake of bettervisualization of the position of inserted parts. It can be seen that theextensions 44 of the two sidewalls 42 of the main portion 40 areembedded in the sand 66. The element 60 is held in proper position inthe mold 65 only as a result of the end portions 44 being embedded inthe sand 66 after the material (e.g., wax) of the pattern 69 is removedfrom the mold 65 as a result of heating so that the resulting cavity canbe filled with a molten alloy which is to form part of the removablecomponent of the prosthesis. The specific weight of the core which fillsthe cavity of the casing 40, 41 in the mold 65 is less than the specificweight of molten alloy so that, if the extensions 44 were not embeddedin the sand 66, the element 60 would become detached from the sand andwould float in the introduced liquid metallic material. Anchoring ofelement 60 in the mold 65 must be reliable and accurate because themajor portions of the cheeks 45 and the exposed part of the portion 40should be completely surrounded by the introduced metallic material inorder to ensure that the male detent member will constitute an integralpart of the detachable component of the prosthesis. In other words, thecasting which is obtained upon cooling of introduced molten metallicalloy includes the element 60 as an integral part. The channel forintroduction of molten alloy is shown at 72 (see FIG. 16). When thecavity which is obtained upon melting of the material of the pattern 69is filled with liquid metallic material and such material is thereuponallowed to set, the projecting metallic portion 73 (surplus) whichextends beyond the phantom line 71 of FIG. 17 is removed by severing orin any other suitable way.

FIG. 14 shows the finished separable crown section 63 which is assembledwith the installed crown section 61 of FIG. 13. The section 63 isattached to the section 61 in that its tapering male portions extendinto the complementary tapering grooves 62 of the section 61. Thesections 61 and 63 are firmly but nevertheless separably held togetherby the male and female detent members 60 and 70 in that the straightfront portion or plunger 48a of the spring 48 in the compartment of thecasing 40, 41 (such compartment receives the spring 48 upon removal ofthe core 77) extends into the recess 70 in the fixedly installed crownsection 61. The holes 46 in the exposed portion of the handle or rib 47serve to receive fastener means (e.g., a U-shaped fastener 76 shown inFIG. 15) which secures the rib 47 to the frame 74 of a yoke or anotherpart of the detachable component of the prosthesis. The frame 74 cansupport one or more false teeth, not shown. The exposed portion of therib 47 is received between two plate-like protuberances 75 of the frame74, and such protuberances are provided with openings registering withthe openings 46 of the rib 47 so as to allow for the passage of legsforming part of the U-shaped fastener 76. The latter can consist ofmetallic wire and is more or less permanently secured to the rib 47 andprotuberances 75 in a manner which is not specifically shown in thedrawing. The connection between the frame 74 and the rib 47 ispreferably concealed (at least in part) by a false tooth (not shown) onthe frame 74.

If the removable component of the prosthesis including the structure ofFIG. 15 is to be detached from the permanently installed component(crown section 61), the wearer or a dentist exerts upon the removablecomponent a pull in an upward direction, as viewed in FIG. 15, so thatthe front portion 48a of the spring 48 is extracted from the recess 70.

FIG. 18 shows the casting core 77 in the compartment of a casing whichis similar to the casing 2. The core 77 comprises a U-shaped handle 78which is accessible for engagement with a tool to facilitate extractionof the core 77 from its compartment upon completion of the work which isinvolved in the making of the detachable component of the prosthesis.Cores of the type shown in FIG. 18 can be used by dental technicians forthe making of the entire removable component solely by hand, i.e.,without making a wax pattern and without resorting to the mold 65 ofFIG. 16. When the core 77 is removed, the compartment of the casing ofthe male detent member is ready to receive a serpentine spring, such asthe spring 48 of FIG. 10. Of course, the core 77 can also be used inconnection with the making of a detachable component in a manner asdescribed in connection with FIGS. 16 and 17.

The provision of the casting core 77 is advisable and advantageousbecause, at least in many instances, the male detent member 1 butespecially that which is shown in FIG. 14 will be incorporated into acast metallic part of the detachable component of a dental prosthesis.Such casting core is a prefabricated part which can be mass-produced ata reasonable cost and can be readily manipulated by a dental technician,even if it is not provided with the handle 78.

The prefabricating procedure can be extended beyond the mere making ofprefabricated cores 77. Thus, and as described in connection with FIGS.10 to 12, the casing of the male detent member can be made ofprefabricated portions 40, 41 which together form a tubular body (withone end closed by the end wall 43) and surround at least four sides of aproperly inserted core 77. The alloy of the casing is preferablycompatible with the alloy which is poured into the cavity of the castingmold 65 upon removal of the material of the pattern 69 so that the maledetent member is fully integrated into the detachable component 63.During integration, the core 77 ensures that the configuration of thecompartment in the casing remains unchanged so that the compartment canproperly receive the spring 4 or 48. As a rule, the male and femaledetent members will be located in immediate or very close proximity ofthe respective gum G when the two components of the prosthesis areproperly attached to each other, i.e., when the male detent memberengages the associated female detent member. This not only results inconcealment of the detent members but also ensures that the relativelythin male detent member can properly retain the detachable component inan optimum position in the region where the detachable componentreceives and transmits stresses of maximum magnitude. As can be seen ineach of FIGS. 4-6, a portion of the casing of the male detent member canremain exposed so as to constitute a visible part of the detachablecomponent. This is desirable on the ground because the technician canreadily inspect the detachable component for the purpose of ascertainingwhether or not the casing is properly embedded in the cast metallicframe of such component, i.e., the technician can more readily detectthe presence or absence of casting defects. As a rule, the likelihood ofthe presence of casting defects is rather pronounced when the thicknessof the walls of the casing is minimal. This holds especially true if atleast a portion of the casing of the male detent member is formedsimultaneously with the metallic frame of the detachable component ofthe prosthesis. If the casing merely comprises the U-shaped member 40 ofFIGS. 10 to 12 and the wall which is formed by the central panel(between the cheeks 45) of the portion 41 is made during casting of thecomponent 63, the overall thickness of the casing of the finished maledetent member is reduced still further since the casing merely includesthe portion 41 whose sidewalls 42 and bottom wall 43 are integral withthe metallic body or frame of the detachable component.

A prefabricated casing (such as the casing 2 of the male detent member 1shown in FIGS. 1 to 3) can be used with particular advantage forsoldering or otherwise bonding to the prefabricated frame by adetachable component. Such prefabricated casing is preferably closed atall sides except in the region (opening 2d of the casing 2) where theplunger (e.g., the integral front portion 9 of the spring 4) is toextend from the casing and into the female detent member. The entiremale detent member 1 can be prefabricated (including insertion of thespring 4 into the casing 2) and is then attached to the separablecomponent of the prosthesis. This obviates the need for a core duringattachment of the male detent member 1 to the frame of the detachablecomponent.

The mode of assembling the male detent member with the detachablecomponent as shown in FIGS. 10 to 18 is preferred at this time. Thus,the partially or completely prefabricated casing of the male detentmember confines a removable casting core 77 and this detent member isthen integrated into the respective component of the prosthesis duringthe making of the component. Such mode of making a complete detachablecomponent allows for extensive automation and eliminates the need formanual work or reduces the extent of manual treatment of the detachablecomponent to a minimum. It would be particularly tedious to manuallyclose the casing including only the U-shaped portion 40 of FIG. 12 so asto ensure that the casing surrounds four sides of the core.

The exposed portion of the handle or rib 47 on the component 63 of FIG.17 can be removed if it is not needed for connection to the frame 74 ofFIG. 15 or to a like part. The handle 47 is preferably small and narrow;nevertheless, it facilitates proper manipulation of the element 60 whichis to constitute or which is to facilitate the making of the male detentmember in or on the finished component 63. The handle 47 can be made ofa material which melts during the making of the component 63, or of amaterial whose consistency remains unchanged during melting andevacuation of the material of the pattern 69.

If the core 77 is inserted into a pattern resembling a finished maledetent member of the type shown in FIG. 17, it is preferably providedwith one or more anchors which are made of wire or the like and areembedded in the forming sand 66 in lieu of the extensions 44 so that thecore 77 does not begin to float when the material of the pattern of thecasing of the male detent member melts away and is evacuated from themold 65 in order to provide a cavity which is then filled with ametallic alloy to form the casing of the male detent member on the thusobtained detachable component. The extensions 44 serve to adequatelylocate the core 77 in the mold 65 only if the portion 40 retains itsshape during the making of the component 63, i.e., if the portion 40constitutes a constituent of the casing of the male detent member on orin the finished component 63. The provision of anchoring means in theform of extensions 44 is desirable and advantageous if the portion 40 isto form part of the finished component 63 because the extensions 44 arepresent anyway when a sheet metal blank is converted into a U-shapedbody 40 having two sidewalls 42 and a bottom wall 43.

If the attachment is to be used as a means which holds the detachablecomponent exclusively by friction, it is preferably employed primarilyin resiliently mounted telescopic bridges.

FIG. 19 shows a portion of a modified male detent member wherein asubstantially block-shaped spring 204 is bonded to a metallic plunger209. The spring 204 can be made of soft silicone rubber or anothersuitable synthetic plastic material and replaces the serpentine spring.When in use, the spring 204 substantially fills the flat compartment ofthe casing, such as the compartment 2c of the casing 2 which is shown inFIGS. 1 to 3. An advantage of the spring 204 is that its cost is a smallfraction of the cost of a metallic or plastic serpentine spring, andalso that it can be anchored (if necessary) in the casing in a simpleand inexpensive manner, e.g., with a drop of adhesive. Bonding of thespring 204 to the metallic plunger 209 can be carried out in availablemachines. A plastic plunger can be used with equal or similar advantage.

The spring 204 can also be made of natural rubber. All that counts is toensure that the spring 204 nearly completely fills the compartment ofthe casing for the aforediscussed purposes. Complete filling of thecompartment by the spring 204 is not possible because, not unlike aliquid, the material of the spring 204 is not compressible. A very smallclearance between the internal surface of the casing and the externalsurface of the spring 204 suffices to enable the spring to perform itsdual function of biasing the plunger and of nearly completely fillingthe compartment. The plunger 209 need not necessarily be bonded to orpartially embedded in the material of the spring 204; it often sufficesto use a cap-like plunger which remains a separate part afterinstallation in the casing.

FIG. 20 shows a portion of a further male detent member wherein asubstantially block-shaped mass 204' is adjacent to the rear side of ametallic plunger 209. The mass 204' can be made of soft silicone rubberor another suitable synthetic plastic material and is used with aserpentine spring 4. When in use, the spring 4 and the mass 204' atleast substantially fill the compartment of the casing. The latter canbe identical with the casing 2 of FIGS. 1-3 or with the casing 40, 41 ofFIGS. 10-12. An advantage of the mass 204' is that it can practicallycompletely fill that portion of the compartment in the casing which isnot occupied by the serpentine spring. This greatly reduces thelikelihood of growth of bacteria in the interior of the casing.

The mass 204' need not transmit and/or store any forces because allnecessary forces are stored and transmitted by the serpentine spring 4.In this embodiment of the male detent member, the sole purpose of themass 204' is to nearly completely fill the compartment of the casing.

FIG. 21 shows one presently preferred kit for shipment of prefabricatedcomponents of the dental prosthesis from the manufacturer or distributorto customers, e.g., to dental laboratories or to individual technicians.The reference character 300 denotes schematically an envelope (e.g., abox, a bag or another suitable container) for a casting core 77 whichmay be of the type shown in FIG. 18, a portion 40 of a composite casing(such as the portion of FIG. 12) which partially surrounds the core 77in order to reduce the overall dimensions of the kit, a prefabricatedplunger 348a, and a prefabricated spring 348 which resembles the spring48 of FIG. 10 except that it is not integral with the plunger 348a. Itis clear that the spring 348 can be replaced with the spring 204 of FIG.19 or with the spring 4, 204' of FIG. 20 and that the plunger 348a canbe replaced with the plunger 209 of FIG. 19 or 20. If furnished as anelement of the kit of FIG. 20, the plunger 209 may but need not bealready bonded to the spring 204 or 4, 204'. It is equally possible tofurnish the kit of FIG. 20 with a prefabricated portion 41 or withprefabricated portions 40, 41. Still further, the kit can be furnishedonly with a casting core and with a spring (which may be integral withthe plunger) or with a core, a spring and a discrete plunger. Stillfurther, the kit can include a complete casing which still contains acasting core and a spring having an integral plunger, or a casingcontaining a core, a spring and a discrete plunger. The furnishing of aprefabricated casing with a casting core therein is desirable andadvantageous if the casing is to be embedded into the correspondingcomponent of a dental prosthesis in a casting operation rather than bysoldering or with an adhesive. A prefabricated casting core is equallydesirable and necessary if the casing is to be made by the establishmentor the party who has purchased the core and the corresponding spring(with an integral plunger or with a discrete plunger). All that countsis to provide a kit which can greatly reduce the amount of manual workby a technician so as to ensure that the making of dental prostheses canbe simplified and automated as far as possible.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic and specific aspects of my contributionto the art and, therefore, such adaptations should and are intended tobe comprehended within the meaning and range of equivalence of theappended claims.

I claim:
 1. A separable attachment between stationary and removablecomponents of a dental prosthesis, comprising a female detent member inone of the components and a male detent member, said male detent membercomprising a flat hollow casing provided in the other component anddefining a flat compartment having a width greatly exceeding its height,and an opening communicating with said compartment, a flat elasticspring installed in said compartment and having a width approximatingthe width of said compartment, and a plunger biased by said spring andnormally extending from said casing through said opening under the biasof said spring, said plunger being receivable in the female detentmember and the thickness of said spring approximating the height of saidcompartment.
 2. The attachment of claim 1, wherein said plunger containsa metallic material.
 3. The attachment of claim 1, wherein said springcontains a rubber-like material.
 4. The attachment of claim 3, whereinsaid material is silicone rubber.
 5. The attachment of claim 3, whereinsaid spring is bonded to said plunger.
 6. The attachment of claim 3,wherein said spring substantially fills said compartment.
 7. A separableattachment between stationary and removable components of a dentalprosthesis, comprising a female detent member in one of the componentsand a male detent member, said male detent member comprising a hollowcasing provided in the other component, defining a compartment andhaving an opening in communication with said compartment, a springinstalled in and occupying a portion of said compartment, a soft massfilling the major part of the remainder of said compartment, and aplunger biased by said spring and normally extending from said casingthrough said opening under the bias of said spring, said plunger beingreceivable in the female detent member.
 8. The attachment of claim 7,wherein said mass contains rubber.
 9. The attachment of claim 8, whereinsaid mass consists of silicone rubber.
 10. The attachment of claim 7,wherein said compartment has a width which greatly exceeds its height,said spring being flat and its width approximating the width of saidcompartment, the thickness of said spring approximating the height ofsaid compartment.
 11. The attachment of claim 10, wherein said spring isembedded in said mass.
 12. The attachment of claim 7, wherein saidspring, said mass and said plunger substantially fill said compartmentso as to reduce the likelihood of growth of bacteria therein.
 13. Theattachment of claim 7, wherein said plunger is rigid with said spring.14. A kit for the making of a male detent member for use as a part of aseparable attachment between stationary and removable components of adental prosthesis wherein the male detent member is installed in one ofthe components and cooperates with a female detent member in the otherof the components to separably couple such components to each other,comprising a flat hollow casing defining a flat compartment having awidth greatly exceeding its height and an opening communicating with thecompartment; a flat spring insertable into said compartment and having awidth approximating the width of said compartment, the thickness of saidspring approximating the height of said compartment; and a plungerarranged to be biased by said spring upon insertion of the spring intosaid compartment so that the plunger normally extends from the casingthrough said opening under the bias of said spring.
 15. The kit of claim14, wherein said plunger is rigid with said spring.
 16. The kit of claim15, wherein said plunger is integral with said spring.
 17. The kit ofclaim 14, wherein said plunger contains a metallic material and saidspring contains a rubber-like material.
 18. The kit of claim 14, whereinsaid spring is a serpentine spring.
 19. The kit of claim 14, furthercomprising a common envelope for said casing, said spring and saidplunger.
 20. The kit of claim 14, further comprising a casting coreremovably received in said compartment and being replaceable with saidspring.
 21. An attachment for separably coupling stationary andremovable components of a dental prosthesis, particularly a frictionalgrip slide attachment, comprising a female part arranged to be affixedto one component of the prosthesis; and a complementary male partarranged to be affixed to the other component of the prosthesis, one ofsaid parts having a female detent member and the other of said partshaving a male detent member separably connectable with the female detentmember to maintain said parts in predetermined positions relative toeach other, said male detent member including a flat hollow casingdefining a flat compartment having a width greatly exceeding its heightand said casing having an opening in communication with saidcompartment.
 22. The attachment of claim 21, further comprisinig aplunger insertable into said compartment, and means for yieldablybiasing said plunger, said biasing means being receivable in saidcompartment inwardly of said plunger and being arranged to bias aportion of said plunger beyond said opening and into said female detentmember in said predetermined positions of said parts relative to eachother.
 23. The attachment of claim 22, wherein said biasing means has awidth approximating the width of said compartment and a thickness whichapproximates the height of said compartment.